Where is the DEEPEST metro in the world In St. Petersburg!

The Northern Capital is the world record holder for its subway system's depth: it is on average 60 meters deep!

The subway stations are built at such a depth, because the upper ground layers under the city are moist and unreliable. The hydrological network of St. Petersburg includes about 100 rivers and canals with a total length of almost 300 kilometers. There are also underground palaeovalleys - traces of a not